1. Technical Field
The present invention relates to an ink container which is mounted on an ink jet recording apparatus and is capable of supplementing an ink composition.
2. Related Art
In the related art, there has been known an ink jet recording apparatus which records images or the like on a recording medium with minute ink droplets discharged from nozzles of a recording head for ink jet recording. The ink jet recording apparatus includes an ink container (for example, an ink cartridge) for supplying an ink composition to the recording head.
As such an ink container, there has been known a refill (pouring) type ink container (a so-called continuous supply type ink container) in which a continuous supply type ink container is refilled with an ink composition instead of replacing the ink container, as well as a replaceable ink container (a so-called ink cartridge) in which the ink container itself is replaced, when an ink composition in the ink container is equal to or less than a predetermined amount. For example, in JP-A-2012-148511, there is disclosed an ink jet recording apparatus which supplies ink from a continuous supply type ink tank to an ink jet head through an ink supply tube, and the ink tank has an ink-refillable structure.
In the continuous supply type ink tank as disclosed in JP-A-2012-148511, an ink chamber for housing the ink composition is provided therein. In such an ink chamber, a support (such as a rib) is provided in order to hold the shape of the ink container and to improve the strength or rigidity thereof in some cases.
The continuous supply type ink container as disclosed in JP-A-2012-148511 is a so-called atmosphere open type container in which an ink chamber is opened to the atmosphere. Thus, an interface (gas-liquid interface) between the air present in the upper side of the ink chamber and the ink is generated in the ink chamber.
Here, when the ink in the ink chamber is consumed, the ink attached to the support is dried by coming into contact with air present in the upper side of the ink chamber and thus it is easy to form a thin film. The formed thin film is easily peeled and the peeled thin film forms aggregates in the ink in some cases. As a result, the aggregates are supplied to the head and then it results in clogging the head (nozzle).
In addition, there is a case where a filter for capturing foreign substances such as aggregates is provided in a flow path of the ink container. In a case where an ink cartridge type ink container which is replaceable instead of ink refill is used, even though the aggregates are captured by the filter, the ink container is replaced before the captured aggregates interfere with the ink supply in many cases. Thus, the clogging of the filter occurred less frequently. However, since the continuous supply type ink container which can be refilled with ink has a very long period of use compared to the ink cartridge type ink container, inconveniences such as ink supply failure due to the aggregates captured by the filter become apparent easily.
Meanwhile, an ink pouring port of the ink container is opened when the ink is poured into the ink chamber, but even though the ink pouring port is opened, it can be closed without pouring the ink into the ink chamber. In such a case, the air present in the upper side of the ink chamber is switched from the air in the saturated state which has been present so far to air introduced from outside which is not in the saturated state. Particularly, when the ink in the ink chamber is largely consumed, and a ratio of the air present in the upper side of the ink chamber becomes higher, a large amount of the air not in the saturated state is introduced into the ink chamber and thus the ink in the ink chamber is rapidly volatilized. In this case, the ink attached on the support present in the ink is rapidly volatilized and thereby a large amount of aggregates may be generated.